ASTM E1382 PDF
ASTM E() – Standard Test Methods for Determining Average Grain Size Using Semiautomati. Purchase your copy of ASTM E – 97() as a PDF download or hard copy directly from the official BSI Shop. All BSI British Standards. The ASTM Designation: E–97 requires five hundred data points for a given sample and this analysis is time-consuming and tedious for the.
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If measurements were made using only the longitudinal plane, determine the mean value of the measurements. Vibrations, if excessive, must be isolated, particularly for automatic image analysis.
All scratches and smearing must be removed, although very? Anisotropy indexes for the two perpendicular test orientations on the transverse and planar surfaces revealed values of 0. The grain size measurement methods described in the following paragraphs are those known to produce results with acceptable precision and minimal bias. Grain boundary delineation is inadequate for automatic image analysis without extensive editing.
When working with a ee1382 alloy composition or a new etchant, it may be helpful asfm measure the grain size as a function of etch time, or other experimental conditions, to develop a reliable practice 10 that agrees with manual determination of the grain size in accordance with Test Methods E The cementite grain boundary?
The mean lineal intercept length,? NOTE 1—Equations 2 and 3 are for single phase grain structures. Test Methods E and Ref 1 3 list many suitable etchants. Store the areas of each grain in memory. If the grain size varies within the product, specimen and? Only whole grains should be in the test area. Drop the measurement grid onto the photograph to prevent placement bias. Such images exhibit grain contrast or color differences between grains rather than grain boundary delineation.
ALA grain size; anisotropy index; area fraction; ASTM grain size number; austenite grains; automatic image analysis; calibration; chord length; confidence level; digitizing tablet; duplex grain structures; equiaxed grains; etchant; ferrite grains; grain boundary; grains; grain size; intercept length; intersection count; magnification; non-equiaxed grains; polycrystalline; prior-austenite grain boundaries; relative accuracy; semiautomatic image analysis; skeletonization; standard deviation; twin boundary; watershed segmentation.
Then calculate the mean lineal intercept,? In general, coarse-grained specimens are more easily etched for prior-austenite grain size.
L, or the mean lineal intercept intersections per unit length, P length,?
Semiautomatic Digitizing Tablet The number of intersections of the grain boundaries by the scan lines is determined. A reasonable estimate of the grain size may be obtained by measurements made on the longitudinal plane only, depending upon the manner in which the grain shape has been distorted.
Alternatively, a greater number of micrographs can be made and analyzed. There may be other possible methods, or other equivalent procedures, that can be used to measure grain size. Discrimination of grain boundaries but not twin boundaries using image amendment techniques may be possible with some automatic image analyzers. Round off the grain size number to the nearest tenth unit. Take the micrographs at random, that is, without bias in the? These measurements are made for a large number of grains, or all of the grains in a given area, within a microscopical?
Ais obtained from the three N specimen, N three principle planes: Automatic Image Analysis e13822 Grain contrast 1 and tint etchants 1,2 are very effective because they generally provide full delineation of the grain structure.
Unmounted specimens generally should have a surface area much larger than required for measurement to facilitate leveling, if automatic image analysis is to be utilized, as described in However, because of the tedious nature of this analysis, for a sufficiently large number of grains to achieve adequate statistical precision, this method is not recommended.
In practice, it is equations for P generally easier to make P counts intersections of test lines with grain boundaries than N counts interceptions of test lines with grains. Automatic image analyzers are affected by these problems to a greater degree than are semiautomatic digitizing tablet measurements. However, these techniques must be used with caution because skeletonization can produce false grain boundaries and watershed segmentation may not produce grain boundaries between two adjacent grains with similar color or gray level.
Either semiautomatic or automatic image analysis devices may be utilized to perform the measurements. There are a number of missing grain boundaries that must be added before measurement.
ASTM E1382 – 97(2015)
Definitions of Terms Specific to This Standard. For example, for optically anisotropic materials that are difficult to etch, crossed polarized light may be required to observe the grain structure.
Next, divide Li by the true? The number of whole grains e13822 per micrograph is Ni. If measurements were made on only a single plane, for example, the longitudinal plane, report that this was aztm and the nature of the test method, plus the statistical evaluation of the data.
To avoid possible confusion, it may be advisable to list the test planes as subscripts, for example, Ap ; or, determine the average grain area on each? L only will be presented. Round off the value of G to the?